there is a way
go to the custom tab and select ''his skin'' then drag the S all the way to the left, and if you want it lighter move the L around until you find something that suits you
hope this helps ;)

Wow, thanks for that! I don't know why I didn't notice that one before.

One more question: How would one replace the penis with something else? There's this thing with Homestuck fans called a 'tentabulge', and while they are technically a tentacle, they don't look like the tentacles in typical hentai. They look more like... well, tentacles. They don't have penis heads.

Any way to replace the penis? If not, thanks for the help already given!